Attack of the Mutagen Man
by Musical Ninja
Summary: During his time in the tank, Timothy sees that Donnie is hurt and sad. He finds that the main reason is April O'Neil and becomes angry. He swears vengeance. And, through the mutagen, it might be possible. And it doesn't help that April is, seemingly, trying to replace Donnie with someone new. My version of "Mutagen Man Unleashed". From Tmnt 2012 season 2.
1. A Kind Yet Broken Heart

**Disclaimer :** I do not own "Teenage Mutant Ninja Turtles". The franchise is property of Nickelodeon studios. If I did own the franchise, I probably would have given the 2012 version have had at least one or two more seasons.

 **Author's Note :** For some reason, I started wonder what "Mutagen Man Unleashed" would have been like if Timothy had wanted to kill April rather than make her his friend. To be honest, it never made sense to me that he wanted April to be his friend. From where I stood, every subject of April made Donnie, Timothy's real friend, sad. I would think that he would want revenge for that; might just be me though.

Anyway, I hope this story is good. Be honest. I only have one rule: No Flames.

* * *

 **A Kind, Yet Broken, Heart**

It was late at night when Leo, Raph, and Donnie heard a sound coming from the living room, which they guessed was the TV. Curious as to what was on, the three older turtles ventured into the living room and found Mikey sitting in front of the TV watching an animated show that they had never seen before with a crate next to him. From where they stood, it looked kind of ridiculous.

"What the heck is this nonsense?" Raph asked, "It's terrible."

"Terribly awesome!" Mikey declared, and then stood up and picked up the crate. He carried to crate over to his brothers and said, "I found these old tapes in a dumpster."

"Tapes?" Raph asked.

"Check it out. The show is called "Super Mecha Force 5"," Mikey explained as he held the crate out to his brothers.

Donnie picked up a tape and inspected it while Leo commented, "Dude, this is awful. And you guys complained about "Space Heroes"."

"Their lips don't even match what they're saying," Raph scoffed, "I could never watch a show this bad."

"Are you _sure_?" Mikey asked, doubting his brother's words.

"I'm positive," said Raph with confidence, "And I can prove it. If you actually get me to watch at least five episodes of this show, I'll give you first slices of the next ten pizzas we order."

"You sure you wanna make a wager like that, Raph?" Donnie asked, "You might end up having to go through with it."

"Donnie, trust me, I now what I'm doing," said Raph, and then turned back to his youngest brother and asked, "So, deal?"

Mikey shook Raph's hand and said, "You got a deal, brother! Say, how about Leo and Donnie watch too? You know, so they're not left out."

The three thought about that for a moment and then answered, "Okay."

All four brothers sat down together in front of the TV and proceeded in watching the video tapes that Mikey had brought home. At first, the brothers were sure that they were right in that they would not get into the show, but, sure enough, they had gotten through four episodes and were in the middle of a fifth, and they were enjoying it; it seemed like Mikey won.

"So, that girl is the princess of an entire planet?" Raph asked. He smiled and added, "Cool!"

"Yeah," said Mikey, "And she also pilot's the robot's left leg. She rules! But that scientist dude in green made the robot."

Donnie smiled at the show and commented, "The story has such an intricately layered plot. Four stars!"

No sooner did Donnie say that when the next scene started to play. In the scene, the scientist was asking the princess out to dinner. Unfortunately, the princess harshly refused and walked away, leaving the poor scientist crushed. Donnie looked upset by the scene while Leo, Raph, and Mikey started laughing their butts off at the scientists' misfortune.

"Oh, Donnie, that's so you and April, dude!" Mikey said between laughs.

"It is not!" Donnie snapped. He then got up and walked away as he said, "Ah, this show is lame anyway. The plot makes zero sense. I'll be in the lab."

And with that, Donnie stormed off to the lab, leaving his brothers in the living room to finish watching the show; seemingly oblivious to how hurt their brother was at the moment.

* * *

Once he was in the lab, Donnie decided to get to work on the retromutagen to cure April's father, Kirby. Before he started, Donnie caught sight of the pictures on the wall. Several of them were of him and his brothers, there were a few of the three of them and Splinter, and one of just Splinter. His eyes landed on a single picture on the wall inside a frame with hearts around it. It was a picture of him and pushing April on the swing in the park, and they both looked very happy in it. He remembered Leo taking that picture; April said she had a great day that day. He smiled for a moment, but his smile faded almost as quickly as it appeared when he remembered that, currently, April resented him and his family.

"What am I to April, anyway?" Donnie asked no one in particular, as he took the picture off the wall, "I'm worse than a nerd. I'm a freak! To her, we're all total complete frea-"

He stopped in mid sentence when he realized Timothy could hear him. Feeling bad for upsetting his formerly human friend, Donnie walked over to the tank, put his hand on the glass, and said, "Sorry, Timothy. I didn't mean to upset you. I'm just frustrated."

Saddened by his friends emotional state, Timothy started liking the glass on the tank, right where Donnie's hand was resting, as though trying to comfort him. Donnie misinterpreted his actions as him signaling hunger and dropped some snacks into Timothy's tank and then put the picture down on the work table. As Timothy ate the food Donnie gave him, he could more clearly see how hurt Donnie was and felt bad for him. He glanced over at the table and saw the picture of Donnie and April. He glared as he thought about how hurt and sad Donnie was and knowing that she was the reason. Donnie did not seem to notice as he started working on his latest retromutagen.

As he worked, Donnie told his friend, in an encouraging manner, "Don't you worry, Timothy. I'm going to create a cure, a retromutagen. I swear, I'll do everything in my power to make you human again. Along with April's dad and any other mutants out there." Timothy was glad to see Donnie happy for a moment, and Donnie's smile faded as he let out a sad sigh and said, "Not that it really matters in April's eyes. Even if I cure every mutant in the world, she'll only see me and my brothers as the guys who mutated her father. But, regardless, I'm going to help you and the other mutants, my friend."

This comment made Timothy even madder. How could someone be so cruel to someone so kind? He wondered. Timothy could no longer stand to see his friend this hurt and sad. He wanted to help, but there was very little he could do. He could not simply reach out a hand of reassurance or offer a comforting hug for he was trapped in his tank. And even if he could get out, if he tried to hug his friend, Timothy would accidentally burn him. So how could he help his friend? He wondered.

Donnie added a drop of his latest retromutagen batch to some regular mutagen and waited to see what happened. To his surprise, the mutagen froze and them shattered the beaker.

"Frozen?! Darn it! Another batch lost!" Donnie yelled in frustration as he pounded the table, "I'm not giving up. I'm going to make you and Mr. O'Neil human again, Timothy. If it's the last thing I do."

Donnie got up from his desk and walked away to get some more supplies, leaving his barely human friend alone with the picture and the mutagen. Timothy continued to stare at the picture of April with a hateful glare as he thought about how sad Donnie was. This girl was the cause of it! She hurt Donnie, a kind and caring being! She had to pay! He thought. But how?

His eyes landed on the canister, which still had a small amount of mutagen left inside. Curious, Timothy reached his lips outside of his tank through the small opening, which Donnie used for feeding, and moved it into the canister. Once he got his lips close enough, Timothy slurped up the mutagen and swallowed it. After the chemical reached his stomach, Timothy felt his body start to change; he began to feel physically stronger. Timothy now knew what he could do for his friend; he could avenge his pain. All he needed was more mutagen.

Suddenly, he heard footsteps and looked up to see Donnie returning to his work station with a box in his hands.

"I'm back, Timothy. I just had to grab some more beakers and a microscope. I also had to grab a couple of petri dishes-" Donnie said, then stopped in mid sentence when he saw that his canister was now completely empty. He scratched his chin and said, "That's funny. I was sure there was still mutagen in there."

Timothy momentarily worried that Donnie might figure out what he did and get mad at him. Luckily for him, Donnie simply shrugged it off and said, "Guess I was mistaken. Oh well, that just means I'm free for the rest of the night. Wanna do something? Blink once for 'yes' and twice for 'no'."

Timothy immediately blinked his eyes once to say, 'yes', happy to spend time with his friend. Donnie and said, "Great. What would you like to do? Maybe read a story from a comic book?"

To that, Timothy blinked once. In response, Donnie went to his comic book collection and showed his friend what he had. He told Timothy to blink once if it was one he wanted to hear and twice for one he did not want to hear. The first two comics were 'no's, but he got a 'yes' on the third. Donnie and saw that he had showed him "Major Justice".

Donnie smiled and said, "Good choice, Timothy. This guy's my favorite! He rules! You know, he started as weak and skinny; sickly even. But, he always had a good heart and only wanted to help others. So, when he was chosen to be the first super soldier, he finally had a chance to make his dream come true when the formula made him physically stronger. When I was little, I wanted to grow up to be just like him."

As Donnie told the story, Timothy could see why this hero was Donnie's favorite. In a way, they were a lot alike; Donnie was not as strong as his brothers, but he had a good heart filled with kindness and compassion. Timothy also saw how Donnie's face lit up as he talked about his favorite hero; he liked seeing his friend this happy. After he was done explaining the hero to Timothy, Donnie positioned himself in front of the tank in a way that he could read the lines to Timothy and Timothy could see the pictures. Donnie wound up reading the comic book to Timothy until he became so tired that he had to go to bed. He bid his friend goodnight and then went to his room.

After Donnie left, Timothy looked back at the picture and growled. Though Donnie could not hear it, Timothy made a vow.

 _"Donnie's pain will end. April O'Neil will be destroyed."_

* * *

 **Author's Note :** For those who are wondering, "Major Justice" is a parody of "Captain America".


	2. Trying to Let go if the Past

**Author's Note:** In this chapter, I will be focusing on April trying to live an average life. Unfortunately, what she fails to realize is that letting go of the past is not easy. Well, here it is. I hope it's good. Please say so.

* * *

 **Trying to Let Go of the Past**

The next day, on the surface, things were pretty normal at Roosevelt High School. Students and teachers were going to classes like normal. Several people were pretty interested in gossiping about the "falling lights" from Friday night. However, one girl was not interested in such a subject. In facts was avoiding it like the plague. The girl's name was April O'Neil.

The night of the "falling lights" was the night she lost her father a second time. This time, he was mutated by one of the falling mutagen canisters landed on her father and he was mutated into a bat-like creature. After he mutated, she learned that the falling mutagen canisters was caused by the turtles. Though it was not intentional, in April's view, the beings she called her friends had turned her father into a monster. She had not seen or spoken to them since.

Today, her hope was to put the past behind her and get back to a regular life. When she reached her locker, April unlocked it and grabbed her books as she talked out loud to herself.

"This is it, April. A new start," April said as she grabbed her books, "Just pretend you're a normal girl. Don't talk about alien robots, or mutant dads. And don't even _think_ about turtles."

Suddenly, April stepped on something that made her fall down backwards with a yelp. She groaned as she looked around for whatever it was that made her fall. She discovered a spinning hockey puck; no doubt that was what she had stepped on.

"Are you serious?!" April asked out loud in irritation.

She then saw a boy with dark brown hair use a goalie stick to move the puck away. "Nice job stoppin' my puck like that," said the boy, with a smile, "You got some skills, Red."

April stood back and glared at the boy while saying, "Um, you could start with sorry."

"Sorry you got in the way," said the boy, pushing his puck around, "What were you doing blocking the hall like that anyway?"

"Blocking the-?" April began to ask, surprised that the boy was acting like he did nothing wrong, "Just who exactly do you think you are?"

The boy approached April, leaned on his goalie stick and said, "You're signed up for extra credit, right? Well, rejoice, cause _I'm_ the guy you're gonna tutor."

"Ugh. Great," April said in annoyance.

The boy's smile dropped as he explained, being serious, "Look, if I don't pass trig, they're gonna kick me off the hockey. Nobody else wants to tutor me." He grinned and then added, "They're all intimidated by my supreme awesomeness."

"So this is you asking me for help?" April asked, and then she signed and rolled her eyes and said, "Charming."

For a moment, all the boy did was stare at her and her text book. April wanted to refuse because she the boy mildly annoying. However, he started giving her a pleading look, which started to get her thinking that she really was his last hope for passing. Seeing as he really needed help and she nothing to do after school anyway, April caved.

"Fine," April said with a sigh, "Meet me at the park at seven. Don't be late!"

"It's a date then," the boy said. And then he hit his hockey puck with his stick. The puck flew right at the water fountain, turning it on. The boy cheered when he saw that he turned on the water fountain, and then cringed when he saw the puck hit another student in the face. However, he immediately shrugged and started walking away.

"So, what's your name?" April asked.

The turned to April with a smile and winked at her as he answered, "Casey Jones." And then he walked away, leaving April alone in the hallway.

The wink caught April by surprise. Was this boy flirting with her? She wondered. Well, whatever the case, tutoring this Casey Jones could be a good way to start getting back to her old normal life; before the Kraang, before the Foot, before the Turtles.

Suddenly, her mind wondered to Donatello, the smart turtle. She remembered how he was the one who swore to her that he and his brothers would rescue her father when he was taken by the Kraang. She remembered how he would always answer when she called him. She remembered how he would always help her when she needed help. She even remembered how he was the one who had carried her safely out of the Technodrome. All of those memories started to make her reconsider her decision to leave the team, until she remembered the night of her father's mutation. The anger and rage at the idea of her once friend being the cause started to become stronger. And so, her choice was clear: no more turtles.

April went back to her locker to close it when her eyes landed on two pictures she had left in there. One was of herself and her father, back when he was still human, and the other was of herself on the swing set with Donnie pushing her; she remembered Mikey suggesting that they make two copies, one for each of them. She smiled at the happy memory as she took the picture out of her locker and stared at it. Suddenly, the bell rang, startling April and causing her to drop her books and the picture.

"Oh, right, class," April said to herself as she picked up her fallen items as quickly as possible. She then closed her locker and hurried to class as she continued to talk to herself out loud, "Don't think about them, April. Don't think about _him_. It's time to let go of the past; no more turtles. Besides, I doubt they would want to see me even if I wanted see them."

Miraculously, April made it to her first class on time.

* * *

For the rest of the day, April went to her classes and tried to act as though everything was normal. Unfortunately, she kept on seeing things that reminded her of her former friends.

For instance, her first class was trigonometry and her book cover had a picture of pizza on it; the turtles loved pizza. This made her inwardly wonder why the books could not have a picture of a pie or a cake instead.

Second, she saw a boy putting up on the bulletin board a reminder of the Space Heroes club meeting that Friday. She remembered how much Leo loved that show.

Third, a boy in a purple shirt was working on a science project while another boy in an orange hoodie watched. This scene reminded her of Donnie and Mikey.

Finally, she caught sight of an older student bullying a younger student and was about to step in and help the younger student when another boy beat her to the punch. A boy in a red shirt stood in front of the younger student and told the bully to back off. The bully told the boy in red to stay out of it but the other boy refused to back down. The bully finally gave up and walked away, and, after he was gone, the boy in red helped the other student up and offered to go with him to tell the principal what happened. The kid who was bullied accepted the offer and went with the other kid to talk to the principal. As happy as April was to witness someone standing up for someone they did not know, she was briefly reminded of Raph. He was a tough guy, but was also protective.

April could not wait for the school day to end so that she could head to the park and tutor Casey. Hopefully, focusing on tutoring him would help her forget about the turtles. The way she saw it, was no way she was going to see anything that would make her think of any of the turtles at the park. However, what April did not realize was that in her haste to pick up her books after dropping them, she got her picture of herself and Donnie caught in between the pages of her book.


End file.
